This circuit was found in a 90s Popular Electronics. It is used for the acoustic transmitters of 40 kHz, as several found in this section. Transistors support current equivalents.
The integrated circuit used is a dual 555 CMOS. The circuit is from an English documentation and...
A 3-input OR gate can be made with an LM3900 amplifier, as shown in the figure. The purpose of the...
We found this conventional power source with a regulating transistor in a 2002 documentation. The...